Battery coil construction

ABSTRACT

An improved cell construction is utilized in which a ruffled edge of the negative plate extends longitudinally beyond the edge of the positive plate at one end of the battery coil and a ruffled edge of the positive plate extends longitudinally beyond the edge of the negative plate at the opposite end of the battery coil. Terminal straps are attached to the extending ruffled edges of the respective plates.

I United States Patent 1191 [111 3,790,408 Cromer 1 Feb. 5, 1974 1BATTERY COIL CONSTRUCTION 2,536,699 1/1951 Ruben 137/107 1 1 Inventor:George Crow, Clay, Fla 512351232 [311323 311213..?fi.11111111 .11.?32133[73] Assignee: General Electric Company,

Owensboro Primary ExaminerAnthony Skapars [22] Filed: May 30, 1972Attorney, Agent, or Firm-Nathan J. Cornfeld et a1.

[21] Appl. No.: 257,754

Related US. Application Data 57] ABSTRACT [62] Division of Ser. No.78,807, Oct. 7, 1970, Pat. No.

3,695,935- An improved cell construction is utilized in which a rufflededge of the negative plate extends longitudi- [52] [1.55. CI. 136/13,136/69 n beyond the edge of the positive plate at one end [51] 11111.Cl. H011" 35/16 f the battery coil and a ruffled edge of the positive[58] Field Of Search 136/13-14, 44-45, plate extends longitudinallybeyond the edge of the [36/691 134-135; 29/180 180 183 negative plate atthe opposite end of the battery coil. Terminal straps are attached tothe extending ruffled [56] Reierences C'ted edges of the respectiveplates.

UNITED STATES PATENTS 3,503,806 3/1970 Sugalski 136/13 4 Claims, 3Drawing Figures ll ll ll ll 11 'Lll "l l1: ll ll l. W

BATTERY COIL CONSTRUCTION This application is a division of myco-pending application, Ser. No. 78,807, filed Oct. 7, 1970, patentedOct. 3, 1972, as [1.8. Pat. No. 3,695,935.

BACKGROUND OF THE INVENTION This invention relates to the constructionof an electro-chemical cell and more particularly to the type of cellconstruction in which a negative plate and a positive plate are woundwith appropriate separators into a coil.

In Sugalski U.S. Pat. No. 3,503,806 issued Mar. 31, 1970 and assigned tothe assignee of this invention there is described and claimed aconstruction of a battery coil in which one edge of the negative platelongitudinally extends beyond the positive plate at one end of the coiland one edge of the positive plate extends beyond the negative plate atthe opposite end of the coil. This type of construction permits ease ofconstruction of the battery coil including the attachment of terminalstrips across the exposed edges of the respective plates by a pluralityof welds to improve the ohmic connection between the plate and theterminal strap. The plates used in such coils comprise a fairly thinmetal substrate upon which the active battery is deposited which, ofcourse, results in an overall increase in the plate thickness. A smallportion of the edge to be ultimately exposed is, however, kept free ofthe active material, among other reasons, to assure a good weld of theplate to the terminal strap. This, however, results in a thin exposededge which may be bent during construction, cause injury to assemblersdue to its thin edge, and in some instances, create misalignmentproblems during the winding process.

SUMMARY OF THE INVENTION It is therefore an object of this invention toprovide an improved battery coil construction. Other objects of theinvention will be apparent from the description and the drawings.

In accordance with the invention and in a specific embodiment thereof animproved battery coil construction is provided comprising a positiveplate having one edge thereof ruffled, a negative plate having one edgeruffled, and separator means therebetween. The plates and the separatormeans are wound into a battery coil with the two plates longitudinallyoffset from one another so that the ruffled edge of one plate extendsbeyond the flat edge of the second plate at one end of the coil whilethe ruffled edge of the second plate extends beyond the flat edge of thefirst plate at the opposite end of the coil.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially cutawayisometric view of the invention.

FIG. 2 is an end view of the invention.

FIG. 3 is a partially cutaway view of a portion of the constructionillustrated in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawingsand particularly to FIG. 1, a battery coil constructed in accordancewith the invention is generally illustrated at 2 comprising a positiveplate 10, a first separator 16, a negative plate 20, and a secondseparator 26.

Plates l0 and 20, with separators 16 and 26 therebetween, are spirallywound to form coil 2. Plates 10 and 20 are longitudinally offset fromone another, as well as from separators l6 and 26, to provide anextending edge 12 at one end of coil 2 comprising a continuous exposededge of plate 10 and an extending edge 22 at the opposite end of coil 2comprising a continuous exposed edge of plate 20.

In accordance with the invention, edges 12 and 22 respectively of plates10 and 20 are formed with a ruffled or non-linear configuration as bestseen in FIGS. 1 and 3. This configuration is used to impart strength tothe otherwise thin exposed edge which, in the prior art construction,could be easily bent making subsequent attachment of the terminal strapdifficult. The construction also provides, as best seen in FIG. 2, alarger cross-section of the exposed edge available for welding toterminal strip 30. Terminal strip 30 may comprise, for example, two legportions 32 and 34. Ruffled edge 12 is shown in dotted outline formbeneath the leg portions so that the increased crosssectional area ofruffled edge 12 beneath portions 32 and 34 may be more easilyvisualized. A raised central portion 36 is subsequently attached to theappropriate positive or negative terminal of the battery as the case maybe. The attachment of the terminal straps to the terminals leading tothe outside of the battery case form no part of the present inventionand are therefore not shown. Attachment of the terminal straps toappropriate terminals carried in a battery casing is illustrated in thepreviously mentioned Sugalski patent, US. Pat. No. 3,503,806cross-reference to which is hereby made.

While the exact configuration of the ruffled edge may be variedsomewhat, for example, the ruffles may be of a corrugated or undulatingshape or they may be vshaped or u-shaped. The overall width of theruffle preferably should not be greater than the width or thickness ofthe portion of the plate containing the active material. For example, ina specific embodiment wherein the plate thickness of the portion of theplate containing the active material was about 20-27 mils thick, theruffled edge (which contains no active material) was about 17-18 milswide from peak to peak. In this manner, the overall thickness of theplate and the resulting battery coil is not increased. It should benoted here that, in contrast, the plate thickness at the ruffled edgecontaining no active material is only about 2 mils thick before it isruffled. Hence the reference to this edge in the prior art constructionas a knife-edge.

The ruffled edge on the plate may be formed by placing the plate in apress containing appropriate dies or it may be formed by passing theplate through a pair of rollers having appropriately shaped knurledportions at the point of engagement of the edge portion of the platecontaining no active material.

The resulting ruffled edge construction of the battery coil providesadded strength to the exposed edge portions of the coil; provides anedge on the plate which is safer for an operator to handle in as much asthe thin edge of the plate no longer represents a knife-edge; and theruffled edge also provides a larger cross-sectional area capable ofwelding to a terminal strap of given area thus providing more ohmiccontact between the plate and the terminal strap to reduce theresistance of the battery at this point. In addition, the constructionof the invention provides another benefit in the rolling assembly of thebattery coil. In the previous construction, using a thin straight edgeon one side of each plate, a plate would occasionally become skewedduring the winding process due to the thin edge slipping under thealignment guides which guide the sides of each plate during the rollingoperation to insure the desired longitudinally offset of the positiveand negative plates with respect to each other and to the separatorstherebetween. Using the ruffled plates of the invention proper alignmentof the plates during the coiling operation is assured due to theeffective increase in thickness of the edge of the plate having noactive material adhering thereto.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. An improved elongated cell plate, having two opposed edge portions inthe direction of elongation, for incorporation in a battery coilcomprising a nonruffled main portion containing active material and oneof said edge portions having a rufiled end relatively free of activematerial, said rufiled end of said one edge portion when the plate is incoiled condition defining a plane substantially perpendicular to theaxis of a battery coil incorporating the cell plate.

2. The cell plate of claim 1 wherein the overall width from peak to peakof said ruffled end of said one edge portion of each plate is notgreater than the thickness of the non-ruffled main portion of each platecontaining active material.

3. The cell plate of claim 1 wherein the other of said edge portions isnonrufiled.

4. The cell plate of claim 2 wherein the other of said edge portions isnonruffled.

1. An improved elongated cell plate, having two opposed edge portions inthe direction of elongation, for incorporation in a battery coilcomprising a nonruffled main portion containing active material and oneof said edge portions having a ruffled end relatively free of activematerial, said ruffled end of said one edge portion when the plate is incoiled condition defining a plane substantially perpendicular to theaxis of a battery coil incorporating the cell plate.
 2. The cell plateof claim 1 wherein the overall width from peak to peak of said ruffledend of said one edge portion of each plate is not greater than thethickness of the non-ruffled main portion of each plate containingactive material.
 3. The cell plate of claim 1 wherein the other of saidedge portions is nonruffled.
 4. The cell plate of claim 2 wherein theother of said edge portions is nonruffled.